Timepiece regulating mechanism

ABSTRACT

In a timepiece driven by a vibrator, a spring having a spring constant much lower than that of the vibrator is coupled to the vibrator. The effective length of the spring is adjustable by varying the point of contact between a regulating mechanism and the spring. Adjustment of the vibration frequency can be effected from the exterior of the timepiece and can be carried out stepwise.

United States Patent 1 1 Koike 1 June 5, 1973 541 TIMEPIECE REGULATING2,858,664 11/1958 Heimann ..58/109 x MECHANISM 1,835,391 12/1931l-laefliger.... ..58/109 2,852,909 91958 M K' t 1.... ..58 109 [75]Kenichi mike suwa'guny 2,959,913 ll/1960 ..58/109 7 1 ken, Japan3,016,687 1/1962 Rabinow ..58/109 x [73] Assignee: Kabushiki Kaisha SuwaSeikosha, FOREIGN PATENTS OR APPLICATIONS Tokyo, Japan 247,759 12/1947Switzerland ..58/109 [22] Flled- SePt' 1971 268,588 9/1950SWltZ6l'lalld.... [21] Appl. No.1 180,040 343,901 2/1960 SWlIZ6lland....

' 355,739 8/1961 Switzerland ..58/109 Foreign Application Priority DataPrimary Examiner-Richard B. Wilkinson Sept. 14, 1970 Japan ..45/80021Exami'mistamey W31 Dec. 28, 1970 Japan ....45 120061 Fnedman HaroldKaplan and Dec. 29, 1970 Japan ..45/128120 James K. S1lberman 52 US.c1.....; ......s8/109, 58/23 TF 1 1 ABSTRACT [51] Int. Cl. ..G04b 17/14In a time piece dr1ven by a v1brator, a sprmg havmg a Fleld of SearchTF, 1 16 R, p i g constant much lower than that of the vibrator is58/116 coupled to the vibrator. The effective length of the spring isadjustable by varying the point of contact [56] References cued betweena regulating mechanism and the spring. Ad- UNITED STATES PATENTSjustment of the vibration frequency can be, effected from the exteriorof the tlmep'lece and can be earned 3,540,210 11/1970 Saito e161..58/109 out Step wise 3,429,119 2/1969 Tamaru ..58/113 14 Claims, 11Drawing Figures PATENTEDJUH 5 ms SHEET 1 BF 7 FIG. I

PATENTEDJUMSISYS 3.736.743

SHEET. 2 OF 7 PATENTEDJUH 5 I975 FIG. 4-

sum 5 [IF 7 FIG. 7

FIG. 8

irracr/va LENGTH SPRING 16 BACKGROUND OF THE INVENTION In conventionalfrequency regulating devices for watches driven by means of a vibrator,it has generally been necessary to open the watch case in order toregulate the rate of vibration of the vibrator. The opening and closingof a watch or other timepieces for this purpose is time consuming andresults in the entry of dust to the inside of the timepiece.

Although regulator adjusting means operable from the exterior of atimepiece where the timepiece is driven by a tuning fork are known, ithas been found to Still other objects and advantages of the inventionwill in part be obvious and will in part be apparent from thespecification.

be difficult to adjust the frequency with sufficient precision. In suchconventional devices, the permanent magnet used in combination with thetuning fork is SUMMARY OF THE INVENTION Where a timepiece is driven bymechanical vibration means such as a tuning fork, said vibration meanshaving a spring constant k, a suitable frequency regulating mechanismcomprises a spring, one end of which is coupled to said vibration means,said spring having a spring constant Ak small relative to k, theeffective length of said spring being adjustable over a range such thatthe vibration frequency of said vibration means is variable over adesired range, and means for adjusting the effective length of saidspring.

The spring is conveniently circular and is centered with respect to ashaft on which is rotatably mounted an arm bearing a pin. The pinengages the spring and rotation of the arm changes the point ofengagement, thereby changing the effective length of the spring. The armcan be rotated about the shaft by means of a pawl and ratchet wheelarrangement actuatable by a push rod protruding through the case of thetimepiece. This to provide a means of precisely adjusting a timepiecedriven by a vibrator.

Another object of the present invention is to provide a means ofregulating a timepiece driven by a vibrator where the regulation iscarried out step-wise.

A further object of the invention is to provide a means of regulating atimepiece driven by a vibrator where the regulation is effected from theexterior of the timepiece. v

Yet another object of the invention is a means of regulating a timepiecedriven by a vibrator where the change in frequency resulting fromrotation of an adjusting screw is proportional to the angle throughwhich said screw is rotated.

A still further object of the invention is a means of regulating atimepiece driven by a vibrator where an adjusting means is coupled to anarm of a tuning fork.

The invention accordingly comprises the features of construction,combination of elements, and arrange- BRIEF DESGRIPTION OF THE DRAWINGFor a fuller understanding of the invention, reference is had to thefollowing description taken in connection with the accompanying drawing,in which:

FIG. 1 is a plan view of a frequency regulating mechanism in accordancewith the present invention, coupled to a tuning fork;

FIG. 2 shows a mechanism similar to that of FIG. 1 in which thecurvature of a hairspring can be varied;

FIG. 3 is an elevational view in partial cross-section of the regulatingmechanism of FIG. 2;

FIG. 4 is a plan view of a frequency regulation mechanism mounted on thebase of a tuning fork;

FIG. 5A is a plan view of a regulating mechanism operated by spur gears;

FIG. 5B is a sectional view taken along line SB-SB of FIG. 5A;

FIG. 6 is a plan view of a regulating mechanism operated by a wormandworm gear combination;

FIG. 7 shows diagrammatically how the effective lengths of the springvaries with rotation of an arm;

FIG. 8 shows two functional relationships between the effective lengthsof the spring and the vibration frequency of the vibration means;

FIG. 9 shows a crown gear and spur gear combination making it possibleto compensate for non-linearity in the relationship between theeffective length of the spring and the vibration frequency of thevibration means; and

FIG. 10 shows an embodiment of the frequency regulating mechanism inwhich'the frequency can be adjusted step-wise.

DESCRIPTION OFI'II-IE PREFERRED EMBODIMENTS A frequency regulatingmechanism in accordance with the present invention is shown in FIG. Iand generally indicated by the reference numeral 11 is coupled to atuning fork 12 carrying weights 13 on the ends thereof. The regulatingmechanism 11 is mounted on a shaft 14 and is held thereon by a springloaded washer 15. The mechanism comprises a spring 16 one end of whichis held in a collet 17 on a stud 18 mounted on an arm of the tuning fork12. The other end of spring 16 is fixed in a stud 19 mounted on arm 21which rotates about shaft 14. A second arm 22 which also rotates aboutshaft 14 carries a pin 23. Pin 23 makes contact with spring 16 therebydefining the effective length of the spring as that section betweencollet 14 and pin 23. The function of arm 21 is to establish-thecurvature of spring 16 as a circle slightly smaller than that followedby pin 23. In consequence, pin 23 makes firm but relatively frictionlesscontact with spring 16. Tuning fork 12 is mounted to a base-plate (notshown) by screws 24. The regulating mechanism 11 is mounted to the samebase-plate.

Instead of fixing the adjustable end of spring 16 to a movable arm as isshown in FIG. 1, the adjustable end of spring 16 can be held in the slotof a collet 25 as shown in FIGS. 2 and 3. In this embodiment, arm 22 isheld by wide-headed screw 26 to base-plate 27 with washer 28 between thehead of screw 26 and base-plate 27. The curvature of spring 16 isadjusted by moving the outer end of spring 16 through the slot of screw25.

It is also possible for the regulating mechanism to be mounted on thebase of tuning fork 12 as shown in FIG. 4. Here, one end is fixed to thearm of tuning fork 12 by the collet 17. The other end of the spring 16is held in collet 29 which is mounted on the base of the tuning fork l2.

Although the position of arm 22 may be varied manually, it is preferablethat the arm be positioned from a location exterior to the regulatingmechanism and more preferably from a location exterior to the timepiece.Such an arrangement is shown in FIGS. A and 53 wherein regulator arm 22is joined to a sector gear 31 which is driven by spur gear 32. Spur gear32 is rotated by a slotted shaft 32' which is external to the mechanismand which may extend through the case of the timepiece.

In another embodiment (FIG. 6), arm 22 is attached to worm gear 33driven by worm 34. Worm 34 is turned by means of shaft 35 whichprotrudes through timepiece housing 36 in the form of a slotted head.Shaft 35 is held in bearings 38.

The formula governing the relationship between the spring constants ofthe vibrating means and the spring on the one hand and the equivalentmass of the vibrator is given by thefollowing formula where, M is theequivalent mass of the vibrator, and Ak is the spring constant of thefrequency regulating spring. The value of Ak is small relative to thatof k; consequently it is possible to adjust the frequency of thevibrating means with great accuracy. Changes in the frequency of thevibrating means are generally due to processing such as the ageing ofthe materials of which the vibrating means is made.

The spring constant of the regulating spring is a function of theeffective length of the spring, but, in general, the relationship isdefinitely non-linear. A typical relationship is shown in curve a ofFIG. 8. The effective length of spring 16 is the portion between pin 23on arm 22 and collet 17. This length is indicated as portion 39 in FIG.7. Arm 22 is represented schematically in this Figure and is shown asbeing positioned at an angle alpha measured from the arm to the linejoining the center of rotation and collet 17.

A means of compensating for the non-linearity between the vibrationfrequency and the angle through which arm 22 is rotated is shown in FIG.9. In the embodiment shown in this Figure, arm 22 is joined with androtates with crown gear 41 driven by spur 42. In this embodiment, crowngear 41 is circular but teeth 43 of crown gear 41 describe a circlehaving a center at 44. As is evident from FIG. 9, center 44 is displacedsubstantially from center of rotation 45 of arm 22. Curve b of FIG. 8shows the relationship between the effective length of spring 16 and thefrequency of vibration of the vibrating means. It is obvious that inthis particular embodiment, the use of the crown gear with displacedcenter is effective in producing a linear function. Needless to say,crown gears with teeth lying on rotation of a shaft. However, it is alsopossible to adjust the regulating mechanism by a translational movementfrom the exterior of the timepiece. Such an arrangement is shown in FIG.10 where regulating arm 22 is i joined to sector gear 31 which is drivenby spur gear 48. Spur gear 48 is a ratchet wheel which operates incombination with the two pawls 49 and 51 at the extremities of shoe 52.Shoe 52 has a slot 53 which receives pin 54. When at rest, shoe 52 isheld away from ratchet 48 by spring 55. Pressure on knurled knob 56forces foot 57 inwardly so that toe 58 makes contact with shoe 52.

In the position shown in FIG. 10, pawl 49 makes contact with ratchetwheel 48 and rotates arm 22 in counter-clockwise direction. Crown 56 canbe rotated through a limited angle to take either of two positions inone of which pawl 49 actuates ratchet wheel 48 and the other of whichpawl 51 actuates ratchet wheel 48.

After actuation of the foot 57,release of crown 56 causes an outwardmovement of shoe 57 as the result of pressure from spring 59. A collar60 limits the outward excursion of foot 57. I

The mechanism of FIG. l0'has the advantage that a single inward andoutward excursion of a foot results in a step-wise change in theposition of pin 23 making contact with spring 16 and thereby causes astep-wise changein the effective length of spring 16. It then becomespossible to calibrate the change in vibration frequency resulting fromeach inward and outward excursion of foot 57. Although regulation isachieved by inward and outward excursion of foot 57, the direction ofthe resulting change in frequency depends on the orientation of foot 57.As stated above, the angle through which foot 57 can be rotated islimited. The most suitable angle is about to hold the rotation to thisangle, a plate 62 is positioned adjacent foot 57. Rotation beyond thedesired limits is achieved by positioning of a plate 62 adjacent foot57. Plate 62 is essentially parallel to shoe 52. Rotation of foot 57beyond the desired limiting positions is present by contact of toe 58with plate 62.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained and,since certain changes may be made in the above construction withoutdeparting from the spirit and scope of the inven tion, it is. intendedthat all matter contained in the above description or shown in theaccompanying drawing shall be interpreted as illustrative and not in alimiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

What is claimed is:

1. In an electrically-powered timepiece wherein a tuning fork having aspring constant k provides the freeffective length of said spring.

2. The frequency regulating mechanism as defined in claim 1, furthercomprising a rod slidably mounted in said timepiece and a pawl andratchet combination operatively connecting said rod and said spring sothat an inward and an outward excursion of said rod causes a stepwisechange in said effective length of said spring and thereby causes astepwise change in said vibration frequency.

3. The frequency regulating mechanism as defined in claim 2, whereinsaid rod is mounted for rotation through a fixed but limited angle toeither of two extreme positions, said rod in one extreme position beingdisposed to increase said vibration frequency and in the.

other'extreme position being disposed to decrease said vibrationfrequency, said changes in frequency being effected by an inward andoutward excursion of said rod.

4. The frequency regulating mechanism as defined in claim 2, whereinsaid rod protrudes through the exterior of said timepiece and isactuatable from the exterior of said timepiece.

5. A frequency regulating mechanism as defined in claim 1, wherein saidadjusting means comprises a member adjacent said spring and movable tomake contact with said spring at any desired point thereof, therebydetermining the effective length of said spring.

6. The frequency regulating mechanism as defined in claim 2, whereinsaid spring is essentially circular and said member comprises a centralshaft, an arm rotatably mounted on said shaft and a pin mounted on saidarm at a radial distance suchthat it makes contact with said essentiallycircular spring.

7. The frequency regulating mechanism as defined in 8. The frequencyregulating mechanism as defined in claim 7, wherein said firstand-second gears are a worm I gear and worm combination.

claim 3, wherein said adjusting member further comv prises a first gearmounted on said shaft, a second gear engaging said first gear and meansfor rotating said second gear, thereby rotating said first gear andadjusting the point of contact between said pin and said spring.

in claim 7, wherein said second gear is rotatable by means exterior tosaid timepiece.

l1. Thefrequency regulating mechanism as defined in claim 3, furthercomprising a second arm mounted rotatably on said shaft, said second armhaving proximate the end thereon a collet in which that end of saidspring not attached to said vibration means is slidably mounted, therebymaking it possible to adjustthe curvature of said spring. v

12. The frequency regulating mechanism as defined in claim 3, whereinsaid mechanism comprises a base plate and a collet fixed to said baseplate, the end of said spring not attached to said vibration means beingslidably mounted in said collet thereby providing'for adjustment of thecurvature of said spring.

13. In an electrically-powered timepiecelwherein a mechanical vibrationmeans other than a balancewheel escapement and main-spring combinationprovides the frequency on which the timepiece rate is based, saidmechanical vibration means having a spring constant k, a frequencyregulating mechanism, comprising a spring one end of which is coupled tosaid vibration means and having a spring constant Ak small relative tok, the effective length of said spring being adjustable over a rangesuch that the vibration frequency of said vibration means is variableover a de: sired range, and means for adjusting the effective length ofsaid spring.

14. A frequency regulating mechanism as defined in claim 13 where saidspring is directly and permanently coupled'at one end of said effectivelength thereof to said vibration means.

1. In an electrically-powered timepiece wherein a tuning fork having aspring constant k provides the frequency on which the timepiece rate isbased, a frequency regulating mechanism, comprising a spring one end ofwhich is coupled to said tuning fork and having a spring constant Deltak small relative to k, the effective length of said spring beingadjustable over a range such that the vibration frequency of said tuningfork is variable over a desired range, and means for adjusting theeffective length of said spring.
 2. The frequency regulating mechanismas defined in claim 1, further comprising a rod slidably mounted in saidtimepiece and a pawl and ratchet combination operatively connecting saidrod and said spring so that an inward and an outward excursion of saidrod causes a stepwise change in said effective length of said spring andthereby causes a stepwise change in said vibration frequency.
 3. Thefrequency regulating mechanism as defined in claim 2, wherein said rodis mounted for rotation through a fixed but limited angle to either oftwo extreme positions, said rod in one extreme position being disposedto increase said vibration frequency and in the other extreme positionbeing disposed to decrease said vibration frequency, said changes infrequency being effected by an inward and outward excursion of said rod.4. The frequency regulating mechanism as defined in claim 2, whereinsaid rod protrudes through the exterior of said timepiece and isactuatable from the exterior of said timepiece.
 5. A frequencyregulating mechanism as defined in claim 1, wherein said adjusting meanscomprises a memBer adjacent said spring and movable to make contact withsaid spring at any desired point thereof, thereby determining theeffective length of said spring.
 6. The frequency regulating mechanismas defined in claim 2, wherein said spring is essentially circular andsaid member comprises a central shaft, an arm rotatably mounted on saidshaft and a pin mounted on said arm at a radial distance such that itmakes contact with said essentially circular spring.
 7. The frequencyregulating mechanism as defined in claim 3, wherein said adjustingmember further comprises a first gear mounted on said shaft, a secondgear engaging said first gear and means for rotating said second gear,thereby rotating said first gear and adjusting the point of contactbetween said pin and said spring.
 8. The frequency regulating mechanismas defined in claim 7, wherein said first and second gears are a wormgear and worm combination.
 9. The frequency regulating mechanism asdefined in claim 7, wherein said first and second gears are a crown gearand spur gear combination, the shape of said crown gear being such as tocompensate for any non-linearity in the effect of said effective lengthof said spring on said vibration frequency so that the change invibration frequency occasioned by rotation of said second gear isproportional to the angle through which said second gear is rotated. 10.The frequency regulating mechanism as defined in claim 7, wherein saidsecond gear is rotatable by means exterior to said timepiece.
 11. Thefrequency regulating mechanism as defined in claim 3, further comprisinga second arm mounted rotatably on said shaft, said second arm havingproximate the end thereon a collet in which that end of said spring notattached to said vibration means is slidably mounted, thereby making itpossible to adjust the curvature of said spring.
 12. The frequencyregulating mechanism as defined in claim 3, wherein said mechanismcomprises a base plate and a collet fixed to said base plate, the end ofsaid spring not attached to said vibration means being slidably mountedin said collet thereby providing for adjustment of the curvature of saidspring.
 13. In an electrically-powered timepiece wherein a mechanicalvibration means other than a balance-wheel escapement and main-springcombination provides the frequency on which the timepiece rate is based,said mechanical vibration means having a spring constant k, a frequencyregulating mechanism, comprising a spring one end of which is coupled tosaid vibration means and having a spring constant Delta k small relativeto k, the effective length of said spring being adjustable over a rangesuch that the vibration frequency of said vibration means is variableover a desired range, and means for adjusting the effective length ofsaid spring.
 14. A frequency regulating mechanism as defined in claim 13where said spring is directly and permanently coupled at one end of saideffective length thereof to said vibration means.